/Engine/Source/Editor/BlueprintGraph/Public/BlueprintEditorSettings.h
Delegates called to determine whether a class type is allowed
void RegisterIsClassAllowedDelegate ( const [FName](API\Runtime\Core\UObject\FName) OwnerName, [FOnIsClassAllowed](API\Editor\BlueprintGraph\UBlueprintEditorSettings\FOnIsClassAllowed) Delegate )